Phototrap complexes are protein structures localized in the membranes of photosynthetic cells. These structures house the molecules necessary for the photochemical reaction of photosynthesis. In this proposed research, phototrap complexes will be isolated from spinach leaves and from photosynthetic bacteria Rhodospirillum rubrum. Chromatium and Rhodopseudomonas viridis. These complexes will be analyzed as follows: 1) the polypeptide composition of each complex will be determined; 2) the chlorophyll, quinone and transition metal composition of each complex will be dettermined; 3) polypeptides of each complex will be isolated for amino acid analysis; 4) a laser-electron spin resonance (esr) spectrometer will be used for a detailed optical- esr investigation of the primary photochemical reaction in these complexes; 5) the laser-esr apparatus will be used to study the temperature dependency of the rate of electron transport in these complexes. A subsequent study will be the design of model systems to simulate photosynthetic electron transport reactions. The eventual utilization of this research will be the construction of "solar cells" from these models for the efficient conversion of sunlight into useful energy.